Various machines have been devised for the melting and spinning of meltable materials, especially sugar. The meltable material may be introduced into a spinning head of the spinning machine in solid form. The material is melted therein just prior to being spun out from the spinner head where it solidifies in the air. The process of melt spinning sugar is most commonly seen in the manufacture of floss-like cotton candy.
Typical cotton candy spinning machines include a spinner head having a generally cylindrical apertured wall. Sugar in solid form, is introduced into the spinner head where it is melted. Spinning of the spinner head causes the melted sugar to be spun out through the apertures in the cylindrical wall where it solidifies into a floss-like structure which has become to be known as cotton candy. The characteristic shape and consistency of the spun material is influenced by several factors. These factors include the size and construction of the spinner head, the size, arrangement and location of the apertures in the cylindrical wall of the spinner head, as well as the manner in which heat is applied to the spinner head.
Numerous machines, designed specifically for spinning cotton candy, have employed various modifications of the spinner head construction in an effort to yield spun product.
U.S. Pat. No. 4,872,821 discloses a cotton candy spinning machine including a spinner head having stacked, slotted, cylindrical walls and coiled heating elements adjacent each wall. Sugar in solid form is introduced into the spinner head and propelled against the heating elements where it is melted. The molten sugar is spun out through the slots where it solidifies into the floss-like material known as cotton candy.
U.S. Pat. No. 3,930,043 discloses a machine which includes a helical resistance heating element positioned within a finely perforated shell. The heating element is supported against the inner wall of the shell by spacer elements. As the shell spins, molten sugar is extruded through the perforations. Similar machines are disclosed in U.S. Pat. Nos. 3,073,262 and 3,070,045.
U.S. Pat. No. 3,856,443 discloses another type of spinning machine wherein the perforated shell through which sugar is extruded functions as the resistance element of the heating means.
U.S. Pat. No. 1,541,378 discloses a spinning machine including a heating ribbon positioned within a helically wound wire. The heating ribbon melts the sugar, which then passes through the interstices thereof and then between the coils of the helically wound wire.
U.S. Pat. No. 1,489,342 discloses a spinner head having an annular heating element formed of a strip of electrical resistance material. The strip is bent as a flat spiral structure forming slanted stretches of heating element having narrow slots between them. The heating element melts the sugar which then passes through the slots between the stretches of the heating element and out through an apertured shell positioned thereabout. A similar machine is also shown in U.S. Pat. No. 816,055.
U.S. Pat. No. 816,114 also forms a heating element of closely arranged coils or folds of a ribbon type resistance heater. The heater is arranged in an annular configuration and placed against an outer spinner head shell which is formed of a plurality of closely spaced glass rods. The sugar is melted by the annular heating element and passes through the heating element and through the spaces between the glass rods.
While some of the above described machinery may perform satisfactorily for converting granular sugar into a floss-like material in the formation of cotton candy, it does not function entirely satisfactorily for spinning other materials which may have properties quite dissimilar to sugar or for other materials mixed with sugar. Nor does the above-described machinery have the capacity to yield product having a desired shape and size. In recent years, it has been increasingly desirable to spin not only feedstock such as sugar and materials combined with sugar, but also nonsaccharides.
One recently developed method of producing substances having pharmacological properties is disclosed in U.S. Pat. No. 4,855,326. This patent discloses combining sugar with a medicament and spinning the combination into a readily water-soluble floss or fiber. In U.S. Pat. No. 5,011,532, the disclosure concerns oleaginous substances such as vegetable oil, baby oil, margarine, lanolin, cocoa butter and the like, and how their lack of affinity for water is altered by mixing the oleaginous substance with sugar and melt-spinning the mixture in cotton candy spinning machines or the equivalent. As so modified, the products disperse in water forming a colloidal or pseudocolloidal dispersion.
Other disclosures which relate to floss-spinning substances with one or more sugars are found in U.S. Pat. No. 4,873,085, U.S. Pat. No. 5,034,421, U.S. Pat. No. 5,028,632 and U.S. Pat. No. 4,997,856. The products described in the above-mentioned patents are all produced by processing in a conventional cotton candy machine. Conventional machinery, however, may be unacceptable for spinning certain materials for certain uses. Conventional machinery also may not offer the user a choice in the size of the openings through which feedstock material is caused to pass prior to being spun out from the spinner head.
The disclosures of each the above-identified patents set forth herein are hereby incorporated by reference.
One attempt to eliminate undesirable drawbacks of conventional machinery especially with regard to the spinning of feedstock including non-sugars as well as sugars combined with non-sugars, is shown and described in commonly assigned co-pending U.S. patent application Ser. No. 08/192,133, filed on Feb. 4, 1994 and entitled "Method and Apparatus for Spinning Thermo-Flow Materials, which is also incorporated by reference herein. The spinner head described therein is referred to as a "cable head" spinner. The cylindrical wall of the spinner head is formed by a heating element comprising a cable which is helically wound about the axis of rotation of the spinner head. In this way the heating element itself is used as the wall of the spinner head through which the material is projected.
While the device shown and described in the above-identified application overcomes many of the disadvantages found in prior art devices, the heating of a helically wound cable may not provide adequate uniform heating necessary in certain applications. Continuously wound resistance-type heating elements may suffer significant heat loss away from the source of power. This may tend to result in non-uniform application of heat. It has been found that the uniform application of heat is one particularly significant factor in precisely controlling the morphology of the spun product.
In that regard a need clearly exists for spinning machinery which provides the user with the ability to process and spin different types of materials and to produce spun product having desired controlled morphology ranging from microsphere to floss.